if you beat the game without killing a single soul, you get stealth. this can be done at any difficulty. you have to use the mk2 pistol or any non-leathal weapons. frogs in first act count as bosses. use the mk2...to beat laughing beauty heres a tip hide under the bed she cannot grab you there, but make sure she knows your there. crying beauty you can hide under the truck using the mosin-nagnt rifle. it is also a non-leathal weapon. all you need is a little patients. screaming beauty first use the syringe and/or the mk2 pistol. you can also use the syringe on meryl. the will prevent screaming beauty from using meryl againts you. use it on the frogers also. to defeat screaming beauty shoot the doll on her right arm then use it to control her.